1. Field of the Invention
The present invention relates to a new water displacement mercury pump.
2. Discussion of Background and Prior Art
Various types of pumps are well-known in the prior art. In one type of prior art, a tube is inserted into a liquid to be pumped, and a vacuum applied to another end of the tube thus drawing up the liquid. A drawback of this type of prior art suction pump, is that the height of a column of liquid drawn up is limited by the ambient air pressure acting upon a surface of the liquid. Thus, suction pumps even for water are limited to a certain height beyond which suction pumps fail to operate and cavitation occurs. With a heavier liquid, such as mercury, a much smaller liquid column can be supported by the ambient air pressure.
In a second type of prior art pump, a pump assembly is placed at the bottom of a reservoir of liquid. Power lines must be supplied to the pump, as well as a fixed support. A disadvantage of this type of pump is that it must be liquid-proof, since liquid leaking into a motor of such a pump would tend to damage it. Furthermore, in the case where the liquid is mercury, the mercury itself may tend to damage various pump parts and react therewith.
Also known in the art is the conventional laboratory device called an "acid egg", shown in Perry's Chemical Engineers Handbook, 5th Edition, Section 6, page 15. The "acid egg" reference shows an egg-shaped body having a pipe extending from the top wall into the body so as to receive liquid acid collected on the bottom of the body. Air introduced under pressure from another inlet displaces the acid up into the pipe and out of the egg. However, the "acid egg" differs from the present invention, and suffers the drawback of being incapable of operation in a chemical reactor vessel to extract liquid settling to the bottom of the vessel during a chemical reaction in the vessel.